It is known that pressure-maintaining valves are used if pressure is intended to be transmitted between two different lines. This is the case in particular whenever a separation of said two separate pressure lines has to be provided in a reversible manner. It is thus known that, at the end of a pressure line, such a pressure-maintaining valve maintains the pressure in said pressure line as long as an air line is not connected on the opposite side. If the air line is connected, which is customarily undertaken by inserting it into an outlet opening of the pressure-maintaining valve, the pressure-maintaining valve has to open in a corresponding manner and provide pressure equalization for the conveying of compressed air.
A disadvantage of the known solutions is that a relatively great amount of effort is necessary in order to insert an air line into the outlet opening of the pressure-maintaining valve. This great amount of effort results from the counterforce which is applied by the pressure present at the inlet opening of the pressure-maintaining valve. A valve body is thus customarily arranged within a known pressure-maintaining valve, said valve body pressing with a sealant against a sealing surface of a basic body of the pressure-maintaining valve. The corresponding counterforce is produced here from the product of the pressure at the inlet opening of the pressure-maintaining valve and the square of the area within the sealing surface of the sealant.
At high pressures, this may even lead to the counterforce being of such a magnitude that a corresponding insertion is no longer possible at all, and there is therefore a malfunction.